Electronic driving circuit



June 30, 1970 R. w. REICH 3,518,515

ELECTRONIC DRIVING CIRCUIT Filed Sept. 10, 1968 lilwutwfitwvt L NSNSN I I I I Y f. 10 1+ Fig. 5

June 30, 1970 R. w. REICH 3,518,515

ELECTRONIC DRIVING CIRCUIT Filed Sept. 10, 1968 v 2 Sheets-Sheet 3 United States Patent ELECTRONIC DRIVING CIRCUIT Robert W. Reich, Via Noseda 8,

CH6977, Ruvigliana, Switzerland Filed Sept. 10, 1968, Ser. No. 758,818 Claims priority, application Switzerland, Feb. 23, 1968, 2,920/ 68 Int. Cl. H02k 33/10 US. Cl. 318128 9 Claims ABSTRACT OF THE DISCLOSURE An electronic driving circuit, particularly for timepieces, comprising a mechanical oscillator, at least one permanent magnet, a transistor, and a coil arrangement for excitation and drive, wherein the permanent magnet consists of a magnet matrix made up of several plates disposed next to one another. The magnet matrix overswinging the coil arrangement generates a chopped direct voltage or an alternating current voltage in the excitation coil which is rectified and applied to the driving coil by means of a resonance amplifier; the latter may be designed with regard to its resonance curve such that with the correct frequency the correct value of the driving current results.

BACKGROUND OF THE INVENTION The present invention relates to an electronic driving circuit particularly but not exclusively for timepieces and comprising a mechanical oscillator, at least one permanent magnet, a transistor, and coil arrangement for excitation and driving of the gear of time-pieces. v

All previously known electronic time-pieces which are driven via a balance wheel or a rotating oscillator have worked according to the principle of direct current amplification. In an exciter coil, a pulse is produced which causes conduction by the transistor. In dependence on the extent of the excitation pulse there results a driving pulse which drives the rotating oscillator via a driving coil and permanent magnet. The drawbacks of this kind of time-piece have been known for a long time. The level of the driving pulse is on the one hand directly dependent on the level of the excitation impulse and on the other hand on the temperature of the transistor and above all also on the voltage of the battery which powers the transistor circuit. v

. SUMMARY OF-THE INVENTION One object of the invention is to provide a circuit arrangement in which the disadvantageous influences of the temperature and voltage fluctuations are excluded as far as possible. v

A further object of the present invention is to provide a circuit arrangement by which the frequency of the mechanical oscillator is regulated automatically.

'According to the invention there is" provided an electronic driving circuit, particularly but not exclusively for driving time-pieces, comprising an oscillator, one or more permanent magnets, a transistor and a coil arrangement for excitation and drive ef a time-piece, characterised by a permanent magnet matrix made up of several magnets with adjacent magnets magnetised with opposite polarity or similarly in the direction of the effective coil windings, which magnets are disposed next to one another, in the "ice direction of oscillation with nonmagnetic members therebetween and also characterized by a transistor circuit and an alternating current voltage amplifier with resonance frequency or with chopped direct voltage as resonance amplifier with suppressed phase arranged in the transistor circuit corresponding to the frequency resulting from the number of individual poles of the magnet matrix and the frequency resulting with the application to the exciter coil.

BRIEF DESCRIPTION OF THE DRAWINGS Reference is now made to the drawings so as to promote a fuller understanding of the invention.

In the drawings:

FIG. 1 shows a permanent magnet matrix made up of alternating side-by-side opposite polarity magnets;

FIG. 2 shows a permanent magnet matrix made up of side-by-side magnets of the same polarity;

FIG. 3 shows a rotating oscillator with a coil combination for excitation and drive for use in the electronic driv- 1ng circuit;

FIG. 4 shows a rotary oscillator with excitation coil and driving coil disposed diametrically opposite relative to the oscillator axis;

FIG. 5 shows a preferred form of the resonance curve for the resonance amplifier; and

FIG. 6 shows a preferred wiring diagram of the electronic driving circuit using a germanium transistor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The permanent magnet matrix 1 illustrated in FIG. 1 comprises five plate magnets 2 disposed side-by-side and magnetised permanently such that, at the ends of the matrix 1, the ends of alternate magnets 2 have the same polarity while adjacent ends have opposite polarity. Adjacent magnets 2 are spaced apart by non-magnetic strips 3. The non-magnetic strips 3 may consist of adhesive layers or adhesive foils by which the magnets 2 are held together and form the magnet matrix 1.

A similar permanent magnet matrix 1a is shown in FIG. 2. In this case however, the adjacent ends of magnets 2 are of the same polarity.

FIG. 3 shows a rotary oscillator which is used in the electronic driving circuit according to the invention. Such oscillator has a shaft 4 which has rigidly connected thereto two carrier plates 5. On their opposed faces each carrier plate 5 carries a permanent magnet matrix 1 constructed as above-described in relation to FIGS. 1 and 2. In the axial air gap of the magnetic circuit defined by the matrices 1 is disposed a coil combination consisting of an excitation coil 6, and concentrically disposed therein is a driving coil 7. It is of course possible to have the driving coil outside and the excitation coil inside. The excitation coil 6 is so selected in its dimensions that its effective coil width corresponds approximately to the thickness of a magnet 2. V

A rotary oscillator according to FIG. 4 is particularly advantageous because it requires no counter-balance weight. On one side of shaft 4 is disposed a permanent magnet matrix 1 consisting of several magnets which cooperate with the excitation coil 6. On the other side of shaft 4 is a magnet 8 of the same dimensions as matrix 1 but of isotropic magnet material which co-operates with the driving coil 7. Therefore magnet 8 does not have inserts, plates or magnetic strips as does matrix 1.

The effect of this is that upon overshooting of the excitation coil 6 by means of the permanent magnet matrix 1, an alternating voltage or chopped direct voltage is connected to the base of a transistor of the control circuit. A resonance amplifier in the control circuit gives a corresponding output in the driving coil 7 whereby by parallel connection to a diode or by suitable construction of the transistor circuit only pulses of one polarity are effective in the driving coil 7 so that the magnet 8 can be constructed as a normal magnet. In spite of this arrangement however, after 180 oscillations are in the excitation coil 6 due to the magnet 8, no excitation current can be induced as an alternating voltage so that therefore no new driving pulse can occur. Such an arrangement is extremely effective and as it has no counter-balance weight to accelerate, it is very economic in comparison with other arrangements.

With all known circuit arrangements for alternating current, the direct voltage component is inhibited by a capacitor connected in series to the base. Only the pure alternating voltage is induced on the base via the capacitor. With chopped direct voltage this blocking of the direct current component is omitted.

According to the invention very simple and extraordinarily economic time-piece drives can be made which vary only slightly as a result of temperature and voltage variations because the alternating voltage resonance amplifier can be suitable designed. It is already known in the general transistor technology to construct, according to the principle of half supply voltage and collector voltage, alternating voltage amplifiers which are temperaturestable up to +65 C. and which work independently of voltage within wide limits. If therefore the transistor circuit is designed in such a manner that use is made of this principle of half supply voltage on the collector and therefore on the driving coil, then one has an extensive temperature stable and voltage stable circuit arrangement.

The finishing of the permanent magnet matrix consisting of several magnets is very simple. It presents, according to the present day magnet technology, no difficulties at all. Indeed the magnets 2 can be strips of magnetised rubber, magnetised by special magnetising devices.

The shape of the resonance curve is likewise obtainable by any form of transistor technology. In the present example it corresponds approximately to the resonance curve of a band filter. The curve can according to FIG. be such that the differential thereof in the area of the correct frequency f is negative. This correct frequency corresponds to an amplification V which supplies the necessary driving pulse for the maintenance of the oscillations. If now, for example, in consequence of change of temperature the frequency is increased to a higher value f then the amplification diminishes to V and consequently a smaller driving pulse as supplied so that thereby the frequency is again lowered. Inversely with a lower frequency f the amplification increases to V whereby a greater driving pulse is supplied and this leads again to an increase of the frequency. One can also use as a diode a variable-capacitance diode which essentilly stabilises the frequency.

FIG. 6 shows a preferred wiring diagram of the electronic driving circuit according to the invention, using a germanium transistor. In the base-emitter circuit of the transistor 9, the excitation coil 6 and the parallel-connected condenser 10 constitute the excitation oscillatory circuit. In the emitter-collector circuit of the transistor 9, the driving coil 7 in parallel with the condenser 11 constitutes the driving oscillatory circuit. The battery 13 is connected in series with the driving oscillatory circuit. Two serially connected diodes 12a and 12b are arranged parallel to both oscillatory circuits in such a manner that the current flow of the diodes is directed from the positive terminal of the battery 13 to the base of the transistor '9 (if a silicon transistor is used, the current flow of the doides 12a and 12b should be reversed). Resonance occurs when L C L C From overcritically coupling the excitation oscillatory circuit with the driving oscillatory circuit, the two bumps in the selection curve (FIG. 5) result, between which the amplification V producing the driving pulse even necessary for maintaining the oscillations is located.

One advantage of such a construction is mainly that the alternating voltage amplifiers are extraordinarily more effective than pure direct voltage pulse amplifiers. In consequence of the frequency resulting from the alternating pulse sequence in the overshooting of the effective coil windings and from the velocity with which the magnet system oscillates over these coils, the transistor circuit can be designed as a resonance amplifier.

Such a resonance amplifier needs only be excited and then gives always the same pulses in synchronism with the alternating voltage pulses. The resonance amplifier may be so designed with regard to its resonance curve such that, with the correct frequency, the correct value of the driving current results; if the oscillation frequency reduces then the amplification is increased and thereby the oscillation frequency is again increased by the higher driving pulse. If the oscillation frequency is too high then the amplification decreases and the driving pulse becomes smaller. In this way, the direct frequency value of the rotating oscillator is regulated automatically. Since at the output of the alternating voltage amplifier, there is also an alternating voltage which however is not usable for the drive, the faulty phase with a diode which is connected parallel to the driving coil is simply suppressed if the blocking of the false pulse direction by the diodes of the transistor is not already effected.

With the magnets magnetised similarly, a similar alternating voltage amplifier in fact results but only with a preferred direction. The counter-changes are substantially smaller and result only due to the alternating striking with inputand output. One has therefore from the outset a displaced reactance voltage curve with a correspondingly high current, and the counter-current is very small and is easily suppressed by a condenser or by a diode.

Of course, the use of the electronic driving circuit is not limited to the driving of the gear of time-pieces with rotating or pendulum oscillator but extends also to electronically controlled winding mechanisms. Finally any suitable magnetic system may be altered to the form proposed and use made of the alternating voltage resonance amplifier or resonance amplifier for chopped direct voltage.

What I claim is:

1. An electronic driving circuit adapted to drive timepieces comprising a mechanical oscillator, at least one permanent magnet, a transistor circuit, and coil arrangement for excitation and driving the gear of a time-piece, said permanent magnet being a magnet matrix made up of several adjacent magnets magnetised in the direction of the effective coil windings, which magnets are disposed next to one another in the direction of oscillation with non-magnetic members there-between, a voltage amplifier in said transistor circuit being arranged as a resonance amplifier with suppressed phase corresponding to the frequency resulting from the number of individual poles of the magnet matrix and the frequency resulting from the application to the exciter coil.

2. A driving circuit according to claim 1, wherein the magnets are disc-shaped and are held together by a binding means which forms the non-magnetic members.

3. A driving circuit according to claim 2, wherein the binding medium consists of an adhesive.

4. A driving circuit according to claim 2, wherein the binding means consists of adhesive foil.

5. A driving circuit according to claim 1, wherein the magnets and the non-magnetic members are parts of a strip-formed magnetised matrix member of ferro-magnetic material.

6. A driving circuit according to claim 1, wherein the resonance amplifier is so designed that with smaller frequency a higher amplification results and with higher frequency a lower amyplification results for the production of a driving pulse.

7. A driving circuit according to claim 1, wherein the alternating voltage amplifier is designed according to the principle of the half supply voltage as a collector voltage.

8. A driving circuit according to claim 1, wherein the mechanical oscillator is a rotating oscillator in which the exciter side lies diametrically opposite to the driving side, said permanent magnet matrix being disposed on the exciter side and a uniform magnet being disposed on the driving side.

9. A driving circuit according to claim 1, wherein with said adjacent magnets magnetised oppositely before the base of the transistor, a condenser for the suppression of the direct current component is disposed.

References Cited DONOVAN F. DUGGAN, Primary Examiner U.S. Cl. X.R. 

